1. Field of the Invention
The invention is directed to N,N'-di(carbonyl chloride) 5, 6 and 7 membered N,N'-alkylene ureas and a process for the preparation of these compounds.
2. Prior Art
J. N. Tilley et al., U.S. Pat. No. 3,275,618 (1966), teach the preparation of alkylene diisocyanates and intermediates which are N,N'-alkylene allophanyl chlorides. These heterocyclic 1,3-diazo-N-monocarbonyl chlorides are produced by reacting N,N'-alkylene ureas in about equimolar amounts with phosgene. They further teach that excess phosgene can be used but will not react with the hydrogen atom of the second nitrogen atom of the heterocycle to form dicarbonyl chlorides.